Protective effects of anti-CfaB-EtpA-LTB IgY antibody against adherence and toxicity of enterotoxigenic Escherichia coli (ETEC)

Aim Production of IgY antibodies against CfaB-EtpA-LTB (CEL) chimeric protein and evaluation of its protective effects against enterotoxigenic Escherichia coli (ETEC) by in vivo and in vitro investigation. Methods and results Indirect ELISA and immunoblotting methods were applied to assess the immunogenicity and specificity of IgYs and also to evaluate the efficacy of IgYs in binding prevention and neutralizing the heat-labile (LT) toxin of ETEC bacteria. The results indicated that the anti-CEL IgY at a concentration of 2 mg ml(-1) could decrease the bacterial adhesion to HT-29 cells by 74% compared to the control group. At a concentration of 750 mu g ml(-1), the IgY antibody managed to neutralize the disruptive LT toxin effect on the Y1 cell line. At a concentration of 2 mg ml(-1), 81% reduction was observed in the fluid accumulation in the ileal loop assay. Conclusion According to our findings, passive immunotherapy with anti-CEL IgY can prevent bacterial colonization and toxicity, thus facilitating in controlling the enteric diseases caused by ETEC infection.